Gear lubricant and method of making it



' tion to provide lubricants of the type mentioned bricant. V 15 which will give low'tor'que characteristics when This is achieved by various new features, parused in gear cases, transmissions, etc. at low ticularly the use of a certain kind of oxidized petemperatures. I I troleum asphalt along with-oil and calcium soap.

A still furtherobject of our invention is to pro- It is highly desirable to include aluminum soap 20 vide, when this characteristic is wanted, a. lubrl- ,as well. a cant which will not set up in the presence oi! Ex p e of Compositions in accordance, w th water. Another object of our invention is to our invention are as ollows: a provide a lubricant of the foregoing type which Y adheres to=meta1 surfaces ten'aciously. Still. an- I I r Example Example other object of our invention is to provide a gear 1 2 aise lubricant which will not change in con- V P III, P

tency to an objectionableextent-on aging.

- It is also an object of our invention to provide fi w fis i l sg 1% 12% V methodsrof making such lubricants. other and "r sun further objects of our invention will become tfit iifiiiifzilitta-caicnniextant. 2312 21:2

apparent as the description thereof proceeds. fX f B fifl g5RPffffffifffl jjj $2 313 I Many diiliculties have been encountered in pro-. I Wm- I .39 I 4 45 ufacturing procedures to produce lubricants having out of the gear case is affected by the'amount '45 memdAuczd mc I a I a I [2,211,921

UNITED 7 STATES PATENT OFFICE I V 2,211,921' I e I GEAR LUBRICANT AND mirnon or. I MAKING rr I Lawrence '0. Brunstrum and George W. Flint, Chicago, and Frederick H. MacLaren, Calumet I City, 111., and ElmemWade Adams,- Hammond,

Ind., assignors to Standard Oil Company, Chi-' I ca'go, 11]., a corporation of Indiana No Drawing. Application May 17, 1937, Serial No; 143,126 a 12 Claims.- (01. 252-36) I This invention relates to lubricants, and parsuch as are used in certain washing machines. ticularly to lubrlcantsfor gear cases, automotive A lubricant for this 'purpose'must be relatively transmissions and the like. The lubricants of our fluid, so that it will get to the gears and lubriinvention are characterized by the presence of cate them properly, must permit a. very low start- 5 an optimum amount of a particular type of asing torque at low temperatures: must adhere to 5 'phalt along with .other' necessary constituents. the metal so that, in spite of. its fluidity, it will The invention also relates to methods of making not be thrown out of the gear case, must not leak such lubricants. past the shaft which protrudes from the gear It is an object of our-invention toprovide fluid case, must be substantially free from foaming 10 or semi-fluid grease-like lubricants for gear cases, when air is whipped into itby the gears, must not 10 I automotive transmissions and the like which set up intoa solid mass or otherwise increase will have the following 'properties: freedom from in body if water'leaks in, as often happens in leakage of oil throughshaft openings, freedom washing machine practice, and must be free from g from foaming and freedom from soap separation soap separation dificulties. We have secured difficulties. It is a further object of our invenall of th pr p r i s im lta e ly in one luviding satisfactory compounded lubricants for 1 I I gear cases, transmissions and the like. I A large 7 The ,fatty acids, lime and soda. are, of course, 35

' number of-rdifierent characteristics are desired reacted toi'orm soap.

and prior to our invention certain of these de- In orderto'achieveth e combination of desirsired characteristics were believed to be incomable characteristicsrepresented by the above expatiblerwith others. A lubricant which had opamples, years of research, work were necessary 40 timum properties in one respect would beundesince it was necessary to balance various factors 40 sirable in another respect and a cure for one against each other A given change would prodefect would produce another defect. We have duce one desirable result butalso an undesirable found it possible by the use of certain constitu- .result and this led to great difllculties. e'nts in certain proportions and by certain man- For instance, leakage of oil past the shaft lead *ing practically optimum properties in all the of soap and by the amountand type of asphalt. desired respects. The amount of soap affects the consistency or One diflicnlt lubrication problemwhich we viscosity. To avoid leakage we use asphalt, prefhave solved is that of providing satisfactory lu erably oxidized asphalt. This prevents leakage bricantsfor gear cases, particularly gear cases and at the same time prevents soaplseparation.

It also prevents foaming when water leaks into the gear case. Petroleum residuum, as distinguished'from asphalt, causes excessive leakage. It also causes foaming both in the absence of water and in its presence. In order to secure absence of foaming when water leaks into the gear case, it is desirable to avoid the use of untreated distillate oils and low viscosity oils. Also in order to avoid soap separation and consequent foaming, it is desirable to use an additional solubilizer such as aluminum soap, in addition to the asphalt.

Conventional gear greases tend to set up into a solid mass or otherwise increase in body in the presence of water. To prevent this it is necessary to avoid high soap contents, to avoid certain types of oils, to 'use a definite amount of asphalt, preferably between about 20% and about 25%, to use a particular type of asphalt which will be described hereinafter, to avoid neutralization of the asphaltogenic acids contained in the asphalt and to avoid the use of sodium soap in quantities over 10% of the calcium soap used.

To secure low temperature starting characteristics and low torque at low temperatures. it is desirable to use a low viscosity oil, preferably one having a viscosity less than 100,000 seconds Saybolt at the lowest starting temperature. A low cold test or low pour point oil is also desirable from the torque viewpoint.

In order to secure desirable fluidity, the oil should have a high viscosity since high viscosity oils produce increased fluidity in the grease. It is also desirable to use the so-called Oil Gel (a commercial aluminum soap)- in place of other aluminumsoaps for this purpose. To secure desirable aging-characteristics Oil Gel, aluminum stearateor other aluminum soap is also desirable and the optimum is about 20% to 25% of the total soap. This prevents undesirable increase in consistencyon aging, particularly if the soap base is noticeably on the acid side.

A further desirable property is absence of "throwing or, in other words, freedom from the condition in which grease is thrown to the top of the gear case and sticks thereto. This is avoided by producing a high viscosity but nevertheless fluid type grease rather than a gel type grease. This in turn is accomplished by using an oil-asphalt blend of as high viscosity as possible without producing undesirable high starting torques at low temperatures.

Of course. where, in the case of any particular lubricant, certain properties are not essential certain of the above considerations can be ignored.

Not only is the composition of the grease highly important but its method of manufacture is also important. The asphalt is one of the key components and it has been found that there is a very marked difference between various asphalts. Some are highly undesirable in our compositions. Oxidized asphalts are preferable and we prefer asphalts such as those from Mid- Continent crude residuums having melting points within the range 60 F. to -100 F. which-have been oxidized to asphalt by air blowing to increase the melting point by an increment of from F. to 200 F. It is also highly desirable in the manufacturing operation to avoid neutralization of the so-called asphaltogenic acids contained in the asphalt. Lime or other basic material is sometimes used in refining operations to avoid corrosion. Asphalt thus produced contains neutralized asphaltogenic acids and is unsuited for use in our compositions.

Furthermore, in order to accomplish this freefactory is known as No. 1 Korite. This is an asphalt made by taking a 104 1% bottoms from Mid-Continent crude -(70 F. melting point) and blowing it with air to a. 180 F. melting point. The oxidized asphalt (No. 1 Korite) has an A. S. T. M. penetration of 35 at 77 F. and contains about 26-27% of material insoluble in hexane.

The preferred method of manufacturing our lubricant compositions is to make a neutral cup grease from the water, oil. calcium soap and sodium soap, if any, and then gradually grade into this cup grease ablending oil containing the asphalt, oil and aluminum soap. The cup grease base should be neutral or at most slightly alkaline when titrated in the presence of 95% alcohol. Any appreciable excess of alkali reacts with the asphaltogenic acids of the asphalt and the resulting grease sets up into a solid mass or at least increases seriously in body .in the presence of water. 011 the other hand, the cup grease base should not be acid. If it is, the final grease tends to foam and its consistency is unstable, particularly if aluminum soap islnot used. 1

It is important that the aluminum soap be added as a separate soap-oil mixture rather than incorporated directly in the base. The desired structure is completely lost when the aluminum soap is incorporated directly in the base. The preferred manufacturing procedure, as above indicated, is to add the aluminum soap with the blending oil but it can be added as a separate grease or soap-oil mixture, the remainder of the total oil together with the asphalt being separately graded into the composition.

Examples Nos. 1 and 2 above are preferr embodiments of our invention. These products are fluid and do not have any pronounced gel structure. For most purposes a gel structure is undesirable but for some uses it is desirable. An example of a grease in accordance with our invention which has a gel structure is as follows:

Low cold test 300 F. flash lubricating oil... 72.1 Water This gel structure is due largely to the fact that Example No. 3 uses a relatively low viscosity oil-asphalt blend, the overall viscosity of the total oil and asphalt being 55 seconds Saybolt at 210 F. as compared with 70 seconds for Example No. 1 and 78 seconds for Example No. 2.

a For our preferred fluid type lubricants we prefer to use oil and asphalt which when blended together will have a viscosity of from about 60 to about seconds Saybolt at 210 F. Lower viscosities tend to produce gel structures while higher viscosities cause high torque characteristics. Another factor tending to cause gel structure is high soap content. To avoid gel structure it is preferable to keep the calcium and sodium soap content under v Still further examples of greases in accordance with our invention are shown in the following It is not absolutely essential to use aluminum soaps'in makinggreases in accordance with our invention. The aluminum soap does prevent soap separation and is desirable in order to avoid pronounced changes in consistency on aging. However, if the aging consideration is not important for a given grease and if the defined type of asphalt is used to help avoid soap separation,

aluminum soap can be eliminated. The following are examples of compositions which ,do not include aluminum soap:

"Example Example No. N o. 9

- Per cent Per cent Calcium soap 2. 73 3. 39 No. l Korite 39. 6 19.8 Lubricating o 57.42 76.62 Water 25 19 Lubricants can also be made in accordance with our invention which are particularly adapted to use in automobile transmissions. Examples of such products are as follows: 7

Example Exampl No. 10 No. 11

- Per cent Per cent Calcium iatty acid soap 3.6 3. 7 Suliurized lard oil 15.0 Low cold test 300 ll. flash lubricating oil. 20. 76 20.6 S. A. E. 20 lubricating oil 45.2 S. A. E. 50 lubricating oil. 40.56 No. 1 Korite. 19.84 30. 1 Water 24 4 It is desirable that the sulfurized lard oil used in Example No. 10. be neutralized in order to improve the consistency of the lubricant. In any of the above compositions not containing sodium soap, up to 5% or even 10% of the calcium soap can be replaced by sodium soap.

To summarize the situation with regard to the compositions of our. products the following generalized compositions can be listed: I

Maximum Optimum range range Per cent- Per cent Calcium soap"-.. 2-6 2. 5-5 Sodium soa 0-. 6 0-. 5 Aluminum soap- 0-2' 1. O-l. 6 Asp alt 15-30 19-25 Water 0-1 .l5-.5 Lubricating oil To nicks 100 To make 100 The viscosity of a blend of the total on and asphalt should be within the range 50 to 120 seconds Saybolt at- 210 F. and, pa'rticularlyfor my preferred type. washing machine gear case lubricants, preferably within the range 60-90 seconds Saybolt at 210 F.

While we have described our invention in connection with certain specific embodiments thereof, numerous other embodiments-within. the scope r of our invention will occur to those skilled in the art in the light of our teachings.

We claim: r 1. Agea'r lubricant containing not'morethan about 6% calcium soap, sodium soap in amounts not greater than about 10% of, the calcium soap, asphalt containing unneutralized asphaltogenic acids; and oil, together with a critical amount of aluminum soap ranging from about 20% to about of the total soap. v v

2. A gear lubricant containing about 2-6% calcium soap, sodium soap in amounts not greater than about 10% of the calcium soap, aluminum soap in amount equal to about 20-25% of the total soap, about 15-30% asphalt free from neutralized asphaltogenic acids, and lubricating oil to make 100%. 3. A gear lubricant comprising:

Per cent Calcium fatty acid soap 2-6 Sodium fatty acid soap 0.6

Aluminum soap 0-2 Asphalt containing unneutralized asphaltogenic acids. e 15-30 Water 1 0-1 Lubricating oil to make 100' said lubricant being free genie acids.

4. A gear lubricant comprising:

- Per cent Calciumsoap 2.5-5 Sodium soap- 0-.5 Aluminum soap 1.0-1.6

Asphalt containing unneutralized asphaltogenic acids 19-25 Water .15-.5 Lubricating oil h to make 100 said lubricant containing unneutralizedasphaltogenic acids.

5. A gear lubricant comprising:

(.talcium fatty acid soap 2.5-5 Sodium fatty acid soap 0 .-.5 Aluminum soap 1.0-1.6 Asphalt"; 19-25 Water v p y .15-.5 Lubricating oil. to make 100 in which the asphalt is made from crude residuum r neutralized asphalto- Per cent having a melting point within the range from about 60 F. to about 100 F. which has been oxidized to increase its melting point'by an incrementof from about F. to about 200 F.

6. A gear lubricant comprising: c

. Per cent Calcium'soape 2.5-5 Sodium soap 0-.5 Aluminum soap.. 1.0-1.6 Asphalt .Water '.15-.5

Lubricating'oil... to make in which the asphalt contains unneutralized asphaltogenic acids and is made from crude residuum having a melting point within the range from about 60 F. to about 100 F. which has been 5 oxidized to increase its melting point by an increment of from about 80 F. to about 200 F.

- 7. A gear lubricant havingapproximately the following composition:

, Per cent Animal fatty acids 3.78

Lime .523 Dry sodium hydroxide .027 Oil ;Gel (aluminum soap) 1.27 No. 1 Korite (oxidized Mid-Continent as-' phalt) 203 Low cold test 300 F. flash lubricating oil 26.21 S. A. E. lubricating oil 47.4 Water .39

20 in which the asphaltogenic acids in said lubricant are not neutralized.

8. A gear lubricant having approximately the following composition:

Per cent Animal fatty acids 3.31

Lime .456 Dry sodium hydroxide .024 Oil Gel (aluminum soap) 1.35 No. 1 Korlte (oxidized Mid-Continent asphalt); "3.--- 21.5 Low cold test 300 F. flash lubricating oil 23.0

S. A. E. lubricating oil 50.02 Water 134 in which the asphaltogenic acids in said lubricant are not neutralized.

9. A method of making a gear lubricant having the following formula:

' Per cent Calcium soap 2-6 Sodium soap 0.6 Aluminum soap 0-2 Asphalt containing unneutralized asphaltogenic acids 15-30 Water 0-1- Lubricating oil to make 100 which comprises making a substantially neutral cup grease with the calcium soap and part of the oil and then grading in the asphalt, the aluminum soap, and the remainder of the oil, thereby avoiding the neutralization 'of asphaltogenlc acids.

10. A method of making a gear lubricant having the following formula:

Per cent Calcium soap 2-6 Sodium soap.. 0.6 Aluminum soap 0-2 Asphalt containing unneutralized asphaltogenic acids 15-30 Water 0-1 Lubricating oil to make which comprises making a substantially neutral cup grease with the calcium soap and part of the I oil and then grading in a blend of the asphalt,

aluminum soap and the remainder of the oil, thereby avoiding the neutralization of asphaltogenic acids.

11. A method of making a gear lubricant having the following formula:

which comprises making a substantially neutral cup grease with the calcium soap and part of the oil and then grading in the asphalt, the aluminum soap, and the remainder of the oil, thereby avoiding the neutralization of asphaltogenic acids.

12. A method of making a gear lubricant having the following formula:

Per cent Calcium soap 2.5-5 Sodium soap 0.5 Aluminum soap 1.0-1.6 Asphalt containing unneutralized asphaltogenic acids 19-25 Water .15-.5 Lubricating oil to make 100 which comprises making a substantially neutral cup grease with the calcium soapand part of the oil and then grading in a blend of the asphalt,

aluminum soap and the remainder of the oil, thereby avoiding the neutralization of asphaltogenie acids.

' LAWRENCE C. BRUNS'I'RUM.

GEORGE W. FLINT. FREDERICK H. MACLAREN. EIMIER WADE ADAMS. 

